"Very disappointed in British Airways for opening my luggage & taking some special items of mine! Some things are sentimental & not replaceable," Kim tweeted Monday. "What happened to the days when you could lock your bags! We need to get back to that. There's no sense of security & no trust!"

"Shame on you," Kim went on.

In a statement to E! News, the airline said it is currently investigating the incident and noted that the terminal in question "has some of the most sophisticated automated baggage systems in the world, which are able to monitor bags every minute of their time in the terminal. At this stage, we have discovered no evidence to suggest that the bag in question was interfered with at Heathrow."

Prior to the supposed theft, Kim and Kanye West were making their rounds at the Cannes Film Festival, even smooching on the French Riviera while celebrating the premiere of West's new film, Cruel Summer.